Networks that primarily utilize data link layer devices are often referred to as layer two (L2) networks. A data link layer device is a device that operates within the second layer of the Open Systems Interconnection (OSI) reference model, i.e., the data link layer. One example of a common L2 networks is an Ethernet network in which end point devices (e.g., servers, printers, computers) are connected by one or more Ethernet switches or other L2 network devices. The Ethernet switches forward Ethernet frames, also referred to as L2 communications or L2 packets to devices within the network. As the Ethernet switches forward the Ethernet frames the Ethernet switches learn L2 state information for the L2 network, including media access control (MAC) addressing information for the devices within the network and the physical ports through which the devices are reachable. The Ethernet switches typically store the MAC addressing information in MAC tables associated with each of their physical interfaces. When forwarding an individual Ethernet frame, an ingress port of an Ethernet switch typically broadcasts the Ethernet frame to all of the other physical ports of the switch unless the Ethernet switch has learned the specific physical port through which the destination MAC address devices is reachable. In this case, the Ethernet switch forwards a single copy of the Ethernet frame out the associated physical port.
To monitor L2 performance metrics and verify operation, network administrators implement a process referred to as Operations, Administration and Maintenance (OAM), which generally provides the activities, tools, standards and other techniques that involve operating, administering and maintaining connectivity in the L2 computer network. One such OAM tool, referred to as OAM Frame Loss Measurement, standardizes mechanisms for loss measurement in an Ethernet computer network and is described in the Internal Telecommunication Union Telecommunication Standardization Section (ITU-T) recommendation Y.1731, “OAM functions and mechanisms for Ethernet based networks,” May, 2006, which is incorporated by reference herein in its entirety. OAM Frame Loss Measurement as described in ITU-T Y.1731, Section 8, defines the Frame Loss Ratio performance metric to apply to Ethernet frames admitted at the ingress L2 flow point of an L2 connection and delivered to the egress L2 flow point of the L2 connection.